Solution to Chinese garbled Chinese characters read by PHP

Example, solve the problem of Chinese garbled characters in the following program.

 Data test

$link = mysqli_connect('localhost','root','','happy');
if (!$link ) {
 die('Could not connect to MySQL: ' . mysql_error());
}
//Chinese garbled solution - set the default encoding
$link->query("SET NAMES 'UTF8'");

$sql = "select * from subway limit 5";
$result = mysqli_query($link, $sql);
while($row = mysqli_fetch_array($result)){
 echo $row['id'] . " : " .$row['code'] . " : " . $row['name'];
 echo "";
}
mysqli_close($link);
?>

before garbled characters: 1:subwayLine1:?? 2: subwayLine1: ??? 3: subwayLine1: ??? 4: subwayLine1: ???? 5: subwayLine1: ???? The result after solving the Chinese garbled characters: 1: subwayLine1: Xinzhuang 2: subwayLine1: outer ring road 3: subwayLine1: Lotus Road 4: subwayLine1: Jinjiang Paradise 5: subwayLine1: Shanghai South Railway Station

The main thing is this sentence: $link->query("SET NAMES 'UTF8'"); Specify default character encoding.